A liquid-sealed antivibration device includes, in general, a first mounting member, a second mounting member having a cylindrical shape, a vibration-isolating base body which connects the first mounting member and the second mounting member and is made of a rubbery elastic material, a diaphragm which is mounted on the second mounting member so as to form a liquid sealed chamber between the diaphragm and the vibration-isolating base body and is formed of a rubber film, a partition element which partitions the liquid sealed chamber into a first liquid chamber on a vibration-isolating base body side and a second liquid chamber on a diaphragm side, and an orifice flow passage which allows the first liquid chamber and the second liquid chamber to be communicated with each other.
As such a liquid-sealed antivibration device, the following patent document 1 proposes an idea where a partition element by which a first liquid chamber and a second liquid chamber are separated from each other has the following constitution. That is, the partition element includes an annular orifice forming member, an elastic wall made of a rubbery elastic material which blocks a space formed by an inner peripheral surfaces, and a pair of partition plates which is connected to each other via a connecting portion penetrating the elastic wall and sandwiches the elastic wall in the axial direction. Here, the displacement of the pair of partition plates in the axial direction is restricted by the elastic wall.
In such a liquid-sealed antivibration device, the displacement of the pair of partition plates is restricted by the elastic wall. Accordingly, while damping vibrations by making use of a liquid flow effect generated by an orifice flow passage with respect to large amplitude vibrations in a low frequency range, vibrations can be reduced by making use of the reduction of a dynamic spring constant generated by the reciprocating movement of the partition plates with respect to minute amplitude vibrations in a high frequency range.
Patent document 1: JP-A-2009-002433